The proposed pluripotent IMPACTA PERU CTU is a consortium of researchers from the Asociacion Civil Impacta Salud y Educacion (IMPACTA), the Asociacion Civil Selva Amazonica (ACSA), the Hospital Nacional Dos de Mayo (HNDM), and the U.S. Naval Medical Research Center Detachment (NMRCD). The CTU headquarters are located at IMPACTA, a Non Governmental Organization devoted to HIV research, led by Dr. Jorge Sanchez and supported by a cadre of experienced researchers and promising junior investigators. It has been affiliated since year 2000 with the HIV Vaccine Trials Network (HVTN) and the HIV Prevention Trials Network (HPTN), and since 2002 with the AIDS Clinical Trials Group (ACTG). Financial support of over 15 million dollars has been invested by NIH in IMPACTA research sites during the last 5 years for optimal staff training and establishing a comprehensive clinical and laboratorial infrastructure for conducting multiple clinical research projects that meet Peruvian and U.S. regulatory standards. Our mission is to efficiently and ethically conduct the clinical research agenda proposed by HVTN, HPTN, and ACTG at four Clinical Research Sites (CRSs), three of them already network affiliated, namely Miraflores, Lince, and ACSA; and a new site that will strengthen the CTU capability to perform prevention and therapeutic research, namely the HNDM. Areas of particular interest are 1) Phase I to III clinical trials on HIV vaccine candidates or regimens, 2) evaluations of pre-exposure prophylaxis with antiretroviral treatment among uninfected men who have sex with men, 3) interventions to reduce HIV risky behaviors among HIV infected persons, 4) HIV prevention trials using treatment of HSV-2 co-infection to decrease HIV-1 genital shedding, 5) identify and intervene individuals with early/acute HIV infection to prevent HIV transmission or impact on the disease course, 6) evaluate the effectiveness of new antiretroviral regimens, 7) evaluate therapies and therapeutic strategies for treating co-infections and complications, and 8) optimize antiretroviral therapies on the basis of safety, adherence, resistance, and durability of response. Investigators from IMPACTA PERU CTU, who are already contributing to the research agenda of the networks as Scientific Committee members and as chairs of protocols in development, envision this pluripotent CTU to fully develop as a center for excellence in HIV Clinical Research in South America. ADMINISTRATIVE COMPONENT: